Classification from bottom to top is as follows:
94HB/94VO/22F/CEM-1/CEM-3/FR-4
The details are as follows:
94HB: Ordinary cardboard, not fireproof (the lowest grade material, die punching, can not be used as a power board)
94V0: flame retardant cardboard (die punching)
22F: Single-sided half glass fiber board (die punching)
CEM-1: Single-sided fiberglass board (must be drilled by computer, not punched)
CEM-3: Double-sided semi-fiberglass board (except for double-sided cardboard, which is the lowest-end material for double-sided panels. Simple double-sided panels can use this material, which is 5~10 yuan/square meter cheaper than FR-4)
FR-4: Double-sided fiberglass board
Best answer
1.c The classification of flame retardant properties can be divided into four types: 94V—0/V-1/V-2 and 94-HB
2. Prepreg: 1080=0.0712mm, 2116=0.1143mm, 7628=0.1778mm
3. FR4 CEM-3 is the board, fr4 is the glass fiber board, cem3 is the composite substrate
4. Halogen-free refers to the base material that does not contain halogen (fluorine, bromine, iodine and other elements), because bromine will produce toxic gas when burned, which is required by environmental protection.
Five. Tg is the glass transition temperature, that is, the melting point.
The circuit board must be flame-resistant, it cannot burn at a certain temperature, it can only soften. The temperature point at this time is called the glass transition temperature (Tg point), and this value is related to the dimensional stability of the PCB board.
What is a high Tg PCB circuit board and the advantages of using a high Tg PCB
When the temperature of high Tg printed boards rises to a certain area, the substrate will change from “glass state” to “rubber state”, and the temperature at this time is called the glass transition temperature (Tg) of the board. That is, Tg is the highest temperature (° C.) at which the substrate remains rigid. That is to say, ordinary PCB substrate materials not only soften, deform, melt, etc. at high temperatures, but also show a sharp decline in mechanical and electrical properties (I think you don’t want to see this situation in your own products by looking at the classification of PCB boards. ). Please do not copy the content of this site
Generally, the Tg of the plate is above 130 degrees, the high Tg is generally greater than 170 degrees, and the medium Tg is greater than 150 degrees.
Generally, PCB printed boards with Tg ≥ 170°C are called high Tg printed boards.
The Tg of the substrate is increased, and the heat resistance, moisture resistance, chemical resistance, and stability of the printed board will be improved and improved. The higher the TG value, the better the temperature resistance of the board, especially in the lead-free process, there are more high Tg applications.
High Tg means high heat resistance. With the rapid development of the electronics industry, especially electronic products represented by computers, are developing towards high functionality and high multi-layers, which requires higher heat resistance of PCB substrate materials as an important guarantee. The emergence and development of high-density mounting technologies represented by SMT and CMT have made PCB more and more inseparable from the support of high heat resistance of the substrate in terms of small aperture, fine line, and thinning.
Therefore, the difference between general FR-4 and high Tg FR-4 is that the mechanical strength, dimensional stability, adhesion, water absorption, and thermal decomposition of the material are in the hot state, especially when heated after moisture absorption. There are differences in various conditions such as thermal expansion, and high Tg products are obviously better than ordinary PCB substrate materials.
In recent years, the number of customers who require high Tg printed boards has increased year by year.
PCB board material knowledge and standards (2007/05/06 17:15)
At present, there are several types of copper-clad boards widely used in my country, and their characteristics are shown in the table below: types of copper-clad boards, knowledge of copper-clad boards
There are many classification methods of copper clad laminates. Generally, according to the different reinforcing materials of the board, it can be divided into: paper base, cloth base of glass fiber pcb board,
Composite base (CEM series), laminated multi-layer board base and special material base (ceramic, metal core base, etc.) five categories. If used by board _)(^$RFSW#$%T
Different resin adhesives are classified, common paper-based CCI. Yes: phenolic resin (XPC, XxxPC, FR-1, FR
-2, etc.), epoxy resin (FE-3), polyester resin and other types. The common glass fiber cloth base CCL has epoxy resin (FR-4, FR-5), which is currently the most widely used type of glass fiber cloth base. In addition, there are other special resins (glass fiber cloth, polyamide fiber, non-woven fabric, etc. as additional materials): bismaleimide modified triazine resin (BT), polyimide resin (PI) , Diphenylene ether resin (PPO), maleic anhydride imine-styrene resin (MS), polycyanate resin, polyolefin resin, etc. According to the flame retardant performance of CCL, it can be divided into two types of boards: flame retardant (UL94-VO, UL94-V1) and non-flame retardant (UL94-HB). In the past one or two years, with more emphasis on environmental protection, a new type of CCL that does not contain bromine has been separated from the flame-retardant CCL, which can be called “green flame-retardant CCL”. With the rapid development of electronic product technology, there are higher performance requirements for cCL. Therefore, from the performance classification of CCL, it is divided into general performance CCL, low dielectric constant CCL, high heat resistance CCL (generally the L of the board is above 150°C), and low thermal expansion coefficient CCL (generally used on packaging substrates) ) and other types. With the development and continuous progress of electronic technology, new requirements are constantly put forward for printed board substrate materials, thereby promoting the continuous development of copper clad laminate standards. Currently, the main standards for substrate materials are as follows.
①National standards At present, my country’s national standards for the classification of substrate materials pcb boards include GB/T4721-47221992 and GB4723-4725-1992. The standard for copper clad laminates in Taiwan, China is the CNS standard, which is based on the Japanese JIs standard. , released in 1983. gfgfgfggdgeeeejhjj
② The main standards of other national standards are: JIS standard of Japan, ASTM, NEMA, MIL, IPc, ANSI, UL standard of the United States, Bs standard of the United Kingdom, DIN and VDE standard of Germany, NFC and UTE standard of France, CSA of Canada Standards, Australia’s AS standard, the former Soviet Union’s FOCT standard, the international IEC standard, etc.
The suppliers of original PCB design materials are commonly used by everyone: Shengyi\Jiantao\International, etc.
● Accepted documents: protel autocad powerpcb orcad gerber or solid copy board, etc.
● Plate type: CEM-1, CEM-3 FR4, high TG material;
● Maximum board size: 600mm*700mm(24000mil*27500mil)
● Processing board thickness: 0.4mm-4.0mm(15.75mil-157.5mil)
● Maximum processing layers: 16Layers
● Copper foil layer thickness: 0.5-4.0(oz)
● Finished plate thickness tolerance: +/-0.1mm(4mil)
● Molding dimension tolerance: Computer milling: 0.15mm (6mil) Die stamping: 0.10mm (4mil)
● Minimum line width/spacing: 0.1mm (4mil) Line width control ability: ＜+-20%
● The minimum drilling diameter of the finished product: 0.25mm (10mil)
Finished minimum punching hole diameter: 0.9mm (35mil)
Finished hole tolerance: PTH: +-0.075mm (3mil)
NPTH: +-0.05mm (2mil)
● Finished hole wall copper thickness: 18-25um (0.71-0.99mil)
● Minimum SMT pitch: 0.15mm (6mil)
● Surface coating: chemical immersion gold, HASL, whole board nickel-plated gold (water/soft gold), silk screen blue glue, etc.
● Solder mask thickness on the board: 10-30μm (0.4-1.2mil)
● Peel strength: 1.5N/mm (59N/mil)
● Solder mask hardness: ＞5H
● Solder resistance plugging capacity: 0.3-0.8mm (12mil-30mil)
● Dielectric constant: ε= 2.1-10.0
● Insulation resistance: 10KΩ-20MΩ
● Characteristic impedance: 60 ohm±10％
● Thermal shock: 288℃, 10 sec
● Warpage of finished board: < 0.7%
● Product application: communication equipment, automotive electronics, instrumentation, global positioning system, computer, MP4, power supply, home appliances, etc.
Post time: Mar-30-2023